"Investors are in a wait-and-see mode as the prospect of the US tax bill remains cloudy, which is a negative factor for offshore traders," Seo Sang-young, an analyst at Kiwoom Securities, said.

Foreign investors sold a net 300.31 billion won worth of local stocks, while institutions and retail investors scooped up a net 140.9 billion won and 117.3 billion won, respectively.

Tech shares had a mixed day of trading. Market kingpin Samsung Electronics edged down 0.82 percent to 2,796,000 won, and SK hynix, a major chipmaker, scored 1.34 percent to 83,400 won.

Hyundai Motor, the No. 1 automaker, was steady at 160,500 won, and top chemical firm LG Chem slipped 0.51 percent to 319,000 won.

The local currency closed at 1,118.1 won against the US dollar, up 2.5 won from the previous session's close.

Bond prices, which move inversely to yields, fell. The yield on three-year Treasurys added 3.1 basis points to 2.211 percent, and the return on the benchmark five-year government bonds increased 3.2 basis points to 2.417 percent. (Yonhap)